/usr/share/php/Horde/ is in php-horde-icalendar 2.1.2-1ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Horde/Icalendar/
/usr/share/php/Horde/Icalendar.php
/usr/share/php/Horde/Icalendar/Daylight.php
/usr/share/php/Horde/Icalendar/Exception.php
/usr/share/php/Horde/Icalendar/Standard.php
/usr/share/php/Horde/Icalendar/Translation.php
/usr/share/php/Horde/Icalendar/Valarm.php
/usr/share/php/Horde/Icalendar/Vcard.php
/usr/share/php/Horde/Icalendar/Vevent.php
/usr/share/php/Horde/Icalendar/Vfreebusy.php
/usr/share/php/Horde/Icalendar/Vjournal.php
/usr/share/php/Horde/Icalendar/Vnote.php
/usr/share/php/Horde/Icalendar/Vtimezone.php
/usr/share/php/Horde/Icalendar/Vtodo.php